PMID- 10544946
OWN - NLM
STAT- MEDLINE
DCOM- 19991130
LR  - 20191210
IS  - 0300-8177 (Print)
IS  - 0300-8177 (Linking)
VI  - 199
IP  - 1-2
DP  - 1999 Sep
TI  - Calcium efflux from platelet vesicles of the dense tubular system. Analysis of 
      the possible contribution of the Ca2+ pump.
PG  - 7-14
AB  - The ATP dependent Ca2+ uptake of platelet vesicles was inhibited by the two 
      hydrophobic drugs trifluoperazine (TFP) and propranolol (PROP). Inhibition was 
      significantly lowered when Pi was used instead of oxalate as a precipitant agent. 
      When the ATPase ligands substrate (Mg2+ and Pi) were absent of the efflux medium, 
      a slow release of Ca2+ which did not couple with ATP synthesis (passive Ca2+ 
      efflux) was observed. Both, TFP and PROP enhanced the passive Ca2+ efflux. This 
      enhanced efflux was partially inhibited only when Mg2+ and Pi were added together 
      to the efflux reaction media, but it was not affected by spermidine, ruthenium 
      red or thapsigargin (TG). The Ca2+ ionophores A23187 and ionomycin, also enhanced 
      passive Ca2+ efflux. However, in this case, Ca2+ efflux was inhibited just by 
      inclusion of Mg2+ to the medium. Ca2+ efflux promoted by Triton X-100 was not 
      affected by either Mg2+ or Pi, included together or separately into the efflux 
      medium. The ATP <==> Pi measured in the presence of Triton X-100 and millimolar 
      Ca2+ concentrations was inhibited by both TFP and PROP, but not by Ca2+ 
      ionophores up to 4 microM. The data suggest that the observed enhancement of 
      passive Ca2+ efflux promoted by TFP and PROP could be attributed to a direct 
      effect of these drugs over the platelet Ca2+ pump isoforms (Sarco Endoplasmic 
      Reticulum Calcium ATPase, SERCA2b and SERCA3) themselves, as it was reported for 
      the sarcoplasmic reticulum Ca2+ ATPase (SERCA1).
FAU - Teijeiro, R G
AU  - Teijeiro RG
AD  - Division Biofisica, Instituto de Investigaciones Biologicas Clemente Estable, 
      Montevideo, Uruguay.
FAU - Sotelo Silveira, J R
AU  - Sotelo Silveira JR
FAU - Sotelo, J R
AU  - Sotelo JR
FAU - Benech, J C
AU  - Benech JC
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Netherlands
TA  - Mol Cell Biochem
JT  - Molecular and cellular biochemistry
JID - 0364456
RN  - 0 (Enzyme Inhibitors)
RN  - 0 (Ionophores)
RN  - 0 (Isoenzymes)
RN  - 0 (Phosphates)
RN  - 11103-72-3 (Ruthenium Red)
RN  - 214IZI85K3 (Trifluoperazine)
RN  - 37H9VM9WZL (Calcimycin)
RN  - 56092-81-0 (Ionomycin)
RN  - 67526-95-8 (Thapsigargin)
RN  - 8L70Q75FXE (Adenosine Triphosphate)
RN  - 9Y8NXQ24VQ (Propranolol)
RN  - EC 7.2.2.10 (Calcium-Transporting ATPases)
RN  - SY7Q814VUP (Calcium)
RN  - U87FK77H25 (Spermidine)
SB  - IM
MH  - Adenosine Triphosphate/metabolism
MH  - Blood Platelets/drug effects/*metabolism
MH  - Calcimycin/pharmacology
MH  - Calcium/*metabolism
MH  - Calcium Signaling/drug effects
MH  - Calcium-Transporting ATPases/*drug effects/*metabolism
MH  - Enzyme Inhibitors/pharmacology
MH  - Humans
MH  - In Vitro Techniques
MH  - Ionomycin/pharmacology
MH  - Ionophores/pharmacology
MH  - Isoenzymes/drug effects/metabolism
MH  - Phosphates/metabolism
MH  - Propranolol/*pharmacology
MH  - Ruthenium Red/pharmacology
MH  - Spermidine/pharmacology
MH  - Thapsigargin/pharmacology
MH  - Trifluoperazine/*pharmacology
EDAT- 1999/11/02 00:00
MHDA- 1999/11/02 00:01
CRDT- 1999/11/02 00:00
PHST- 1999/11/02 00:00 [pubmed]
PHST- 1999/11/02 00:01 [medline]
PHST- 1999/11/02 00:00 [entrez]
AID - 10.1023/a:1006928110564 [doi]
PST - ppublish
SO  - Mol Cell Biochem. 1999 Sep;199(1-2):7-14. doi: 10.1023/a:1006928110564.